1.5 The Theory of Plate Tectonics



Vocabulary


Plates: Where the Lithosphere is broken into separate parts- called plates.
Scientific Theory: A well tasted concept with lots of observation.
Plate Tectonics: The theory which explains the Formation, movement, and subduction of the plates.
Faults: Cracks in Earth's crust, where rocks have slipped past each other.
Transform Boundaries: Where two plates have slipped past each other.
Divergent Boundaries: Where two plates have moved apart from each other.
Convergent Boundaries: Where two plates have moved into each other, or converged.
Rift Valley: A deep valley that forms along convergent boundaries.

Outline


  • Introduction

    • Lithoshere is broken into pieces/sections seperated by jagged cracks, plates
    • J.Tuzo Wilson thought of concept
  • A theory of Plate Motion

    • Plates are in constant slow motion driven by convection currents in mantle
    • Plate movements create volcanoes, mountain ranges, and deep-sea trenches
  • Plate Boundaries

    • Lines where plates meet are plate boundaries
    • Faults are breads in earth's crust where rocks have slipped past each other
  • Transform Boundaries
    • Crust is neither created nor destroyed
    • Plates slip past each other going in opposite directions
    • Earthquakes occur frequently here
  • Divergent Boundaries
    • Plates move apart, usually occurs in mid-ocean ridge, also on land
    • On land, it creates a rift valley, going deeper and deeper into crust
      • Rift valley will someday drop enough for the sea to come in and fill the gap, seperating the land
  • Convergent Boundaries
  • Plates collide/come together, may bring together oceanic with oceanic, continental with continental, or oceanic with continental crusts.
      • The denser plate dives under the less dense plate (oceanic goes under continental, for oeanic and oceanic the density decides)
      • Continental and continental usually have same density, so they keep squeezing to make mountains
  • The Continents Slow Dance

    • Plates move from one to ten centimeters per year, as fast as fingernails grow
    • Pangea is true, now scientists support the theory
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